<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src="../../vue.js"></script>
</head>

<body>
  <div id="app">
    <h1>{{username}}</h1>
    <!-- <input type="text" v-on:input="username=$event.target.value"> -->

    username:<input type="text" v-model.lazy="username">
    age:<input type="number" v-model.number="age">
    msg:<input v-model.trim="msg">

  </div>

  <script>

    var vm = new Vue({
      el: "#app",
      data: {
        username: "",
        age: 20,
        msg: ""
      }
    })

  </script>

</body>

</html>